Fluorinated fulvalene ruthenium compound for molecular solar thermal applications

Molecular photoswitches, i.e. molecules capable of isomerizing between two states when submitted to light stimuli, has found applications in several areas such as molecular logic, molecular electronics, and, if the two isomers differ substantially in energy, molecular solar thermal (MOST) systems. In a MOST system the photoswitchable molecule absorbs a photon where after a photoinduced isomerisation to a high energy metastable photoisomer occurs. The photon energy is thus stored within the molecule. Fulvalenediruthenium compounds, has been suggested as a candidate in MOST systems thanks to the large difference in energy between the two isomers, its relative stability, and its ability to absorb sunlight. We here present a fluorinated fulvalene ruthenium derivative and show that its processing properties is remarkably different, while having retained photoisomerization efficiency, compared to its hydrocarbon analog.